Pulling water is to use two credit bookmakers with certain backwaters to bet a certain amount on the upper and lower plates of the same booth at the same time, so as to achieve the balance of winning and losing and earn the banker's backwaters. The bigger the bet, the bigger the stagnant water.

Calculation method: Last bid, assuming backwater 1%, betting 1000, water level 1.00, winning or losing 1000. If the backwater 1% and the water level are 0.98, the winner will earn10/kloc-0 * 0.98,10/010.